Even when they're separated from the grind of a NASCAR weekend, Tony Stewart still is chirping constantly at crew chief Steve Addington.

The defending Sprint Cup champion, who moonlights from stock cars by running several dozen dirt-track races annually, rarely misses the chance to fire a barrage of text messages relaying his progress at some dusty bullring.

"All night long," Addington said, laughing. "We get updates everytime he hits the track and every hour on the hour. Sometimes, we're already in bed, and the phone's going off."

The dispatches might have nothing to do with Stewart's No. 14 Chevrolet, but Addington said they reveal an appreciative and nuanced worldview from the driver-owner of Stewart-Haas Racing.

"That's where you take pride in working for him because he understands the business so much," Addington said. "He goes and wins one night with his sprint car and takes the car to a different racetrack the next night and struggles to make the show. So he understands that things are always changing each and every weekend."

A year after winning his third championship and unceremoniously firing crew chief Darian Grubb, it's been a season of wildly vacillating ouctomes for Stewart. He is ranked seventh in the Chase for the Sprint Cup entering Martinsville Speedway as the defending winner of Sunday's Tums Fast Relief 500.

Trailing Brad Keselowski by 47 points with four races remaining, Stewart is unlikely to capture a fourth title in NASCAR's premier series, but he has shown flashes of the form that carried him to five wins in claiming last year's Chase while also exhibiting moments that recall the winless regular season that preceded it.

Meanwhile, Grubb — who led Stewart to wins in three of the final four races a year ago — is back in championship contention with third-place Denny Hamlin (27 points ahead of Stewart).

Addington described his first year as Stewart's crew chief as "feast or famine," and it's perhaps best illustrated by this: Stewart has the same number of top-five finishes (11) as outcomes of 20th or worse.

"I feel like our guys have done a great job of working hard and keeping the morale of the team up," said Stewart, who has three wins but none since July. "Our attitude in our shop is very, very positive right now. We have a really strong group of true racers. They're really keen and savvy when it comes to keeping their morale high and realizing that one bad week doesn't take us out of it until they say we're mathematically out. I feel like they've been giving 100% all along."

That didn't keep Stewart from issuing a stinging rebuke after a slow pit stop last week at Kansas Speedway, where he rebounded to finish a Chase-best fifth.

Addington, though, said such public spankings are part of Stewart's leadership style that can mix enthusiastic cheerleading with sharp criticism.

"He's awesome on supporting you," Addington said. "There's going to be days that we make mistakes, and there's days he makes mistakes, and he understands that."

Addington said the team's biggest shortcoming this season was falling behind on the 1.5-mile superspeedways, where Stewart scored three wins in last year's Chase. He opened this season's 1.5-mile slate with another win at Las Vegas Motor Speedway using last year's setup, but he finished outside the top 10 in the next five 1.5-mile races.

"We kept trying to run stuff we ran in the past, and I think the Hendrick and Penske guys and everyone got to working hard on their stuff to get better to beat the 14 car," Addington said. "I don't think we had a bad package, I just think the other (teams) improved on theirs and made their cars better in certain areas that we were struggling. We're developing a new package, and Tony is getting more comfortable with it, and it's showing each week that we're getting better.

"Every racetrack we go to from here, we have a shot at a win if we can give him something that he can compete with. We've felt that way all year long."